The heat generated by electric/electronic parts negatively affects the parts or the other peripheral parts, undesirably deteriorating the performance of the parts or shortening the lifetime thereof. To solve this problem, a water cooling process using a solvent such as water is utilized to forcibly decrease the temperature of the surface, or a natural cooling process using convection of air is employed on the surface area of parts, which is made large. As such, the water cooling process exhibits very high cooling effects but is disadvantageous because many devices such as additional devices for circulating water and for storing water must be installed, which leads to remarkably increased cost and large-sized installations. Also, the air cooling process manifests very low cooling effects, making it difficult to perform rapid cooling.
Meanwhile, the major reason in which electric/electronic parts have trouble is because of the heat generated by the parts. While a number of parts are carrying out their inherent functions, heat is generated, and there are often cases where such heat causes the parts to go out of service. A typical method of removing the generated heat includes using a fan or mounting a heat-dissipating plate having a large surface area at the end where heat is transferred to. Aluminum, which is mainly used for the heat-dissipating plate, has high heat conductivity, making it possible to efficiently transfer heat from the heat generation source to the surface, but aluminum does not effectively emit heat from the surface because of the emissivity of 30% or less.
Such an electric/electronic part, for example, an LED is receiving attention as a novel light source with low energy and high efficiency thanks to drastic advancement in recent years. However, in order to use the LED as a high-power lighting device, it is most important to solve heat dissipation problems. Although LED chips exhibit high luminous efficiency, the heat value thereof is considerable. Unless heat dissipation methods are provided, LED chips become too hot and the chips themselves or the packaging resin may deteriorate undesirably reducing the luminous efficiency and the lifetime of chips. To retain high efficiency and long lifetime, which are the advantages of LEDs, it is essential to develop techniques for diffusing the heat of chips to the outside.
LEDs, which are currently available, are configured such that heat generated therefrom is dissipated via the heat-dissipating plate provided on the rear surface thereof. Conventional techniques include Korean Patent No. 10-0910917 entitled “heat sink device of LED module for lighting equipment”, Korean Patent No. 10-0670918 entitled “LED lamp having heat release structure”, Korean Patent No. 10-0899977 entitled “heat sink device of LED lamp”, Korean Patent No. 10-0910054 entitled “apparatus for radiating heat of LED lamp”, Korean Patent Publication No. 10-2009-0108222 entitled “LED lighting device having multiple heat-dissipating structure”, etc.
Most such conventional techniques are provided in such a manner that the heat-dissipating plate is formed on the rear surface of the LED or the heat dissipation structure is formed so as to be adjacent to the LED, and thus their heat dissipation designs lay emphasis on forms, coupling structures, configurations thereof, etc., and aluminum is mainly used therefor. Whereas aluminum having high heat conductivity may efficiently transfer heat from the heat generation source to the surface, the release of heat from the surface greatly depends on air convection because the emissivity of aluminum is 30% or less. In the case where the LED is employed in high-power lighting devices, there may still be heat dissipation problems.